The current way to close an engine valve is to use a spring. This is not desirable because of the dynamic motion in engines, which may cause spring wear and various valve train problems that lead to poor power transmission and poor fuel consumption rates. Valve float is one of the valve train problems and refers to the inability of the valve lifter to properly follow the contour of the camshaft when the engine is operating at high speeds. Since the valve actuation is not aligned with the shape of the camshaft lobe, this may result in catastrophic failure or engine damage if the closing valve makes contact with the piston. The other consequences are valve spring harmonics and vibrations that cause the valve to bounce on its seat while trying to open and close. Pivoting rocker arm and valve spring failure is another common malady in high-performance racing engines. Therefore, it is advantageous to employ engine valve actuation that does not require pivoting rocker arms and valve springs for valve closure.
This present invention eliminates or minimizes these problems by using the camshaft lobe at its peak to close the engine valve with positive linkage through the pushrod. Valve float is minimized along with the chance of a piston hitting the engine valve as a result of an engine valve staying open for too long due to weak or malfunctioning valve springs. Another benefit of this invention is more precise valve timing events with custom ground camshafts that are designed to close the valve at its peak more aggressively. Additionally, more radical grinds can be used. As a result of more precise valve timing and smaller valve spring pressure, fuel consumption efficiency in terms of gas mileage is improved.
This present invention uses a vertical sliding valve arm that is activated by the camshaft to close an engine valve and a valve spring to open the valve. This is in contrast to conventional engines, which use the camshaft lobes to open a valve and the valve spring to close it. The invention reverses the function of the valve spring, uses the camshaft lobes to activate a sliding valve arm with the attached engine valves, and uses the valve spring to open the engine valves at the appropriate time. The invention comprises in part a retrofitting system requiring little machine work on an existing engine.